Field of the Invention
The present invention relates to an image quality adjustment apparatus and correction data generation method for generating correction data for correcting display unevenness caused by manufacturing variations, and an image quality adjustment technique using the apparatus and method.
Description of the Related Art
It is known that display unevenness occurs in display panels, such as liquid crystal panels, organic EL panels, and the like, due to manufacturing variation. For example, in the case of liquid crystal panels, it is known that display unevenness occurs due to uneven cell gaps or uneven illumination of the backlight. In the case of organic EL panels, it is known that display unevenness occurs due to uneven illumination of light emitting devices included in respective pixels. In order to provide consumers with a high-quality display panel with reduced display unevenness, an image quality adjustment apparatus is used to measure display unevenness (unevenness data) in advance in the production line, and based on the measured unevenness data, generate correction data. The generated correction data is written to a ROM of a correction circuit incorporated in the display panel. When the display panel is driven according to display data, the correction circuit reads out the correction data, and based on the correction data, corrects the display data, depending on the display panel, so that an image free from display unevenness can be displayed.
In measurement of display unevenness, a predetermined test pattern image is displayed on a display panel, and an image of the displayed test pattern image is then captured using a camera including a CCD (CCD camera). However, the pixels of a display panel and the pixels of the CCD of a CCD camera are arranged in a regular grid pattern, and therefore, unless both of the arrangements completely match, a moire pattern occurs. If correction data is calculated based on a captured image containing a moire pattern, display unevenness cannot be accurately corrected, which is a problem.